cliff. >> unless the president obama and congress can reach a deal by the new year, tax increases and spending cuts will automatically take effect. >> and the clock is ticking. >>> of course, when we look back at this year, president obama's re-election was one of the biggest political stories of the year. all others, you could say, they pealed in comparison. >> with the first of our year-enders, here's abc's karen travers. >> reporter: to win a second term, president obama had to overcome a well funded opponent, a struggling economy, and voters' doubts that he had the right agenda to turn the nation around. [ chanting ] >> all: four more years! >> reporter: and after a roller coaster season, he got them. mitt romney may have started off at the frontrunner, but to win the republican nomination, he had to fend off some feisty challengers. >> he's the worst republican in the country to put up against barack obama. >> the odds are very high i'm going to be the nominee. >> reporter: and overcome some self-inflicted wounds. >> i like being able to fire people who provide services to me. >>